Marriage is really hard and i've only been married for a month. So I think that pretty much says so. But even though it its hard, it could last forever,it may not be a fairy tale but there is something called true love. I have a used-to-be-classmate whose parents have been together for more than 50 years now and if you see them,it's like they were married yesterday. It's incredible how the talk about eachother. A big plus in their marriage is that they have god as the head of their family. They're really christian and I think that when you have god in your live and you really have this high level of spirituality,it helps to keep a marriage strong and to grow stronger. I think the fundamental of a good marriage is: god,love,comunication,respect.
Hope I helped.